Ecosystem Topics

An ecosystem is the combined biological and physical components of an environment and their interrelationship in a particular space. During the last 50 years, humans have changed ecosystems more rapidly than in any other comparable time in human history, reports the World Health Organization. While human needs have been met in the areas of food, fuel, freshwater, fiber and timber, the result has been a largely irreversible loss to the Earth's diversity. Topics about ecosystems generally fall within three categories.

Types of Ecosystems

• There are three main types of ecosystems: terrestrial, freshwater and marine. Topics addressed today concern the continued degradation of all ecosystems and their services, the resulting increase in poverty for certain groups of people in Africa, the Caribbean and Latin America, and appropriate actions that need to take place to reverse the degradation.

Terrestrial Ecosystems

• Degraded land is a terrestrial ecosystem topic. According to the Face the Future website, degradation and deforestation has affected 8.5 percent of the world's forests which are located in South America. Grasslands and forests continue to be degraded for agricultural purposes. Creating and maintaining cropland has displaced one-quarter of the natural grasslands and one-third of the tropical and temperate forests.

Freshwater Ecosystems

• Topics about freshwater ecosystems cover pollution, man-made changes such as irrigation and dam building, and the introduction of invasive species to freshwater. Frog mutations are an example of the results of chemical pesticide and fertilizer use. According to Facing the Future, the use of phosphate fertilizer increased by 203 percent, and the use of nitrogenous fertilizer increased by 638 percent.

Marine Ecosystems

• Marine ecosystem topics include overfishing. Overfishing has not allowed the world's oceans time to replenish the fish supply. According to Facing the Future, half of the word's wild fishing grounds in West Africa and the North Atlantic have been fully exploited and can no longer provide fresh fish. The coral reefs are another topic and part of the marine ecosystem being affected. Coral reefs are home to more than a million fish, other plant species and animals. A coral reef is made up of tiny animals providing a home to zooxanthellae. Increased sea temperatures have caused the zooxanthellae to die, leaving the coral reefs to starve.

Ecosystem Changes

• Changes in the ecosystem have created more topics needing to be addressed. This includes natural disasters that occur with greater destruction and frequency because ecosystems are being disrupted and destroyed. Other topics include the value of ecosystems in dollars and cents. Facing the Future estimates that ecosystems provide a buffer to civilization valued at over $4 billion annually by reducing landslides of all kinds and regulating flood waters, fires, drought and sandstorms.